1. Field of the Invention
The present invention relates to a slender pipe connecting connector and, more particularly, to a connector for connecting a metal pipe or resin tube having a relatively small diameter, e.g., 20 mm or less (as will be generally referred to as a "pipe"), which is to be arranged as an oil or air supply passage for a variety of machines or apparatus.
2. Description of the Prior Art
In the prior art, the connector of the above-specified type is exemplified in FIG. 17. In this connector, a retainer 22 having a pair of elastic pawl walls 23 projecting forward in a converging manner from the end of an axially center mounting hole is retained on a retaining wall 21' formed on the circumferential edge of tile rear end of a connector body 21 such that its stepped portion 24 formed of an annular wall 23' of the rear end of the retainer 22 is retained on the retaining wall 21'. In this assembled state, the pawl walls 23 are made engageable with an annular bulging wall P.sub.o ' which is formed in the vicinity of the connected end portion of a pipe P.sub.o inserted.
According to this prior art, however, the retainer 22 has to have its diameter engaged by its snapping action at the pawl walls 23 to be engaged with the pipe P.sub.o, so that the entire size of the product containing the connector body 21 is enlarged by the snapping function of the pawl walls 23 at the time of connecting the pipe P.sub.o, to invite a difficulty in the arrangement in a narrow place. Along with the large diameter and the snapping function, the pawl walls 23 have to be elongated to weaken the binding force of the bulging wall P.sub.o ' of the pipe P.sub.o and to invite the "permanent strain". This invites an axial looseness under vibrations and frequently causes a tendency to induce leakages.
If, moreover, an intense external force is applied in the extracting direction to the arranged pipe P.sub.o, the pawl walls 23 are curved (or warped) externally, as indicated by phantom lines in FIG. 17, on account of the aforementioned "permanent strain". As a result, the connection grows unstable to raise a problem in the pipe connection required for the retainer 22 to have a sufficient force against an extraction.